Benitez told reporters: “I talked with John on Wednesday morning and he is getting there and can start to do the warm-up with the team soon and then we will see how he will progress.

“Talking to the doctor, the problem is a build-up of fluid on the bone. So at this stage we have no idea when he will be back.”

The Blues skipper is not the only absentee for Benitez, with Chelsea set to lose John Obi Mikel and Victor Moses to the forthcoming Africa Cup of Nations.

Goalkeeper Petr Cech is also sidelined for “two or three weeks” with injury and is expected to miss both legs of Chelsea’s Capital One Cup semi-final against Swansea.

However, striker Demba Ba is close to completing his transfer from Newcastle and Benitez is hopeful he could make his debut against Southampton on Saturday: He added: “If we can do the business I hope he can play in the FA Cup.”